Worldwide emissions of carbon dioxide, widely blamed as the chief cause of global warming, dropped from 2008 to 2009, largely because of the global economic slowdown, according to a study released Sunday. It was the first decline since the late 1990s.

Invoking the spirit of "Star Trek" in a scholarly article entitled "To Boldly Go," two scientists contend human travel to Mars could happen much more quickly and cheaply if the missions are made one-way. They argue that it would be little different from early settlers to North America, who left Europe with little expectation of return.

Space is about to get its first humanoid from planet Earth. Robonaut 2 affectionately known as R2 is hitching a one-way ride to the International Space Station this week aboard the final flight of space shuttle Discovery.

Warmer and wetter weather in large swaths of the country have helped farmers grow corn, soybeans and other crops in some regions that only a few decades ago were too dry or cold, experts who are studying the change said.